Airflow profile study of a compost dairy barn using a low-cost 3D-printed anemometer network

Mechanical ventilation is commonly used for environmental thermal regulation inside closed-field agricultural production systems. Analyzing the air distribution inside these facilities and the correct operation of the fans can be a challenging. This could be determined using cost prohibitive techniques as particle image velocimetry or deploying large wind sensors networks on-site. To avoid this limitation without a lack of measurement accuracy, this research was focused on developing and test a low-cost anemometer network based in low cost propeller’s anemometers, built using fused 3D-printed and open-hardware platforms. Four propeller anemometers with three to six blades were simulated using the 6-DOF method of ANSYS computer fluid dynamics software. Similar results were obtained for all the simulated models with minor differences. Anemometers were tested in an open circuit wind tunnel before to be evaluated in two open compost dairy barn building using high-volume low-speed and low-volume high-speed fans. Data were analyzed by employing contour maps, descriptive statistics and correlation. The results show that the anemometer network determines the fan’s wind profile for wind speeds over 0.7 m s-1 and it was possible to determine the facilities spots with ventilation problems. The proposed anemometer network and methodology are a good alternative to analyze the operating conditions of the tested agricultural facilities and optimize its performance

Decision three to predict respiratory rate of piglets submitted to cold conditions

Received: January 16th, 2021 ; Accepted: March 13th, 2021 ; Published: October 5th, 2021 ; Correspondence: [email protected] subjected to thermal conditions outside their comfort zones may show altered physiological and behavioural responses, which may consequently cause productive losses. For these reasons, the aim of this paper is to develop a decision tree for the prediction of respiratory rate (RR, mov min-1 ) of piglets exposed to different thermal situations. The experiment was carried out in an experimental pig farm of the Universidad Nacional de Colombia Campus Medellin, located at the San Pablo Agraria Experimental Station located in the eastern sector of the department of Antioquia, during August 2019. A database containing the raw data for dry bulb temperature - tdb (°C), and relative humidity - RH (%) as input variables, and RR (mov min-1 ) of six piglets were assessed every two hours as output variable for piglets was generated. The experimental database was composed of 78 observed data. The decision trees were developed to conditions of tdb between 19.2 to 29.5 °C and RH between 50.2 to 88.4%. In the experimental period, RR of piglets submitted to tdb higher than 27.1 °C the RR was around 60 mov min-1 , tdb smaller than 27.1 °C the RR varied from 36 to 46 mov min-1 . These low values of physiological responses may indicate that the piglets are not in a comfortable situation, so their development, welfare and production can be affected. The decision tree developed can be useful to provide a quick understanding of the piglet’s welfare condition based on the environmental variables and physiological responses

Compost-bedded pack barns in the state of Minas Gerais: architectural and technological characterization

ArticleCompost bedding pack (CBP) barns have been receiving increased attention as an alternative housing system for dairy cattle. Thus, a systematic investigation of the primary management practices of dairy cattle in CBP barns in the state of Minas Gerais (Brazil) has proven to be of environmental and economic relevance. The aim of this research was to summarize the compost bed data, barn dimension data and to determine the major interactive factors in the success of bed composting from qualitative and quantitative methods. Data for this study was collected from 16 CBP barns, distributed throughout the southern state of Minas Gerais (Brazil) between March 2017 and July 2018. These data were used to describe the building layouts and dimensions, to identify barn management practices, and to characterize the compost bedding material concerning moisture content. The majority of these barns had feed alleys and driveways; overshot ridges with frequent orientation from NE to SW; bedding process and aeration using mechanical tillage. The average bedding moisture content was found to be 36.9 ± 5.2% (w.b.). Based on the information found, it is possible to evaluate that there is still no defined construction pattern, with a high variation of size and technologies employed

Comparison of airflow homogeneity in Compost Dairy Barns with different ventilation systems using the CFD model

In the pursuit of high milk productivity, producers are using confinement systems in order to improve performance and animal welfare. Among the housing systems, the Compost bedded-pack barns (CBP) stand out. In these barns a bedding area is provided inside, where cows move freely. Generally this area is covered with carbon source material (such as sawdust or fine dry wood shavings) which together with manure, thanks a regular mechanically stirring, ensures the aerobic composting process. The ventilation in these facilities has the function of dehumidifying the air, improving the air quality, drying the bedding, improving the thermal comfort conditions of the confined animals. This work aimed at validating a computational model using Computational Fluid Dynamics (CFD) to determine the best homogeneity of airflows generated by different forced ventilation systems used in CBP barns. Two CBP barns were compared with different ventilation systems: high volume low speed (HVLS) and low volume high-speed (LVHS) fans. The results showed that the proposed model was satisfactory to predict the flows generated by both types of fans. It was concluded that the use of HVLS fans produced a more homogeneous airflow when compared to LVHS fans. The use of mechanical ventilation in tropical conditions is necessary for the proper functioning of the system. In this study, the systems used promoted the increase in air speed to levels close to adequate

Estimate of manure present in compost dairy barn systems for sizing of manure storage

Milk production is increasingly modernized as a result of the growing demand for food around the world. Improvements in livestock facilities are observed, with a large increase in the use of feedlot systems such as the Compost Dairy Barn. Increasing milk production in confinement systems has also raised concerns such as the management of wastes (water, faeces and urine) from the system, which has become one of the most important issues in the intensive dairy farms. The aim of this work was to estimate the amount of manure present in compost dairy barn systems in order to size the manure storage. The study was conducted at four compost dairy barns in southern Minas Gerais, Brazil. These compost barns had different bedding materials and dimensions. In each farm, data on milk yield and quality (daily production, fat and protein content), animal weight and amount of feed ingested by the animals were collected. Total-day manure delivered by the cows in the feeding alley and milking parlour was piled up together and weighed. Based on the results, it was observed that, in the compost dairy barns, only part of the total manure produced per day was delivered in the milking parlour (1.6 and 2.0%) and in the feed alley (27.6 to 49.3%). These results are very important for designers for the proper manure management system design of the dairy farms